<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
		  input{
			  width: 30px;
		  }
		</style>
	</head>
	<body>
		<div id="">
			<input type="text"  class="tex1"/>
			<input type="text"  class="tex2" />
			<input type="text" class="result"/>
			<input type="button" value="+" class="btn1" />
			<input type="button" value="-" class="btn2" />
			<input type="button" value="*"  class="btn3"/>
			<input type="button" value="/" class="btn4" />
		</div>
		
		<script type="text/javascript">
			function bnt(){
				var result=0;
				var num1=Number(document.getElementsByClassName(tex1).value);
				var num2=Number(document.getElementsByClassName(tex2).value);
			
	
		</script>
	</body>
</html>
